Grinding wheel truing mechanism



Aug. 27, 1946. M. DAVIS r 2,406,357

GRINDING WHEEL TRUING MECHANISM Filed May 23, 1945 Patented Aug. 27, 1946 GRINDING WHEEL TRUING MECHANISM Lee M. Davis, Springfield, Vt., assignor to Jones & Lamson Machine Company, Springfield, Vt.,

a corporation of Vermont' Application May 23, 1945, Serial No. 595,369

In the dressing or truing of grinding wheels, it

has been common practice to rock the truing tool laterally across the wheel face, the rocking mounting having the advantage that it is relatively easy to eliminate lost motion in the movement of the elements. This mounting, however, producesa traverse in an arc and while this maybe quite fiat so that in most instances the trued face is sufficiently accurate, in some cases this are is objectionable, particularly where a special highly accurate configuration of the trued face is important, as it introduces troublesome complications in the production of cam surface contours for controlling the truing device motions.

The present invention, therefore, has for an object to so mount'the truing devices that they move in straight lines while at the same time avoiding possibility of lost motion, and yet employ actuating means including pivoted mechanism which can be readily constructed to minimize lost motion effects.

In accordance with this invention, therefore, the truing device is provided with a slide mounted on preloaded ball bearings for motion transverse to the plane of rotation of the grinding wheel and a cross slide also mounted on preloaded ball bearings for motion laterally of the carriage motion, the truing device being carried by the cross slide. The motions of the two slides may then be controlled by pivotally mounted control members.

The advantages of accuracy of control of the pivoted mounting member is thus combined with the straight line characteristics of the slide mountings.

For a more complete understanding of this invention, reference may be had to the accompanying drawing in which Figure 1 is a fragmentary view partly in side elevation and partly in section on line I-I of Figure 2 of a truing mechanism embodying the invention.

Figure 2 is a lateral sectional view on line 22 of Figure 1. 1

Figures 3 and 4 are detail sectional views on lines 3-3 and 4-4, respectively, of Figure 1.

Referring to the drawing, at I is indicated a tubular casing for containing the truing mechanism which is shown as of the general type illustrated in the Flanders Patent No. 2,292,874, granted August 11, 1942, for Wheel truing mechanism. The grinding wheel to be trued is indicated at 2. Closely adjacent to the grinding wheel the casing I is provided with a transverse partition 3 having a slot 4 therethrough for the slidable reception of a stem 5 to the outer end 2 Claims. (01. 125 11) 2 of which, outwardly of the partition 3,-the truing tool Bis fixed. A flexible diaphragm I secured about its margin to the partition 3 and toward its center to the stem 5 provides a seal for the slot 4 to prevent the passage of foreign matter back through the slot 4 into'contact with the mechanism enclosed by the casing This stem5is secured to a slide amounted for movementlongitudinally of the stem 5-on preloaded ball bearings 9 positioned between the outer edges of the slide 8 and marginal upstanding walls ID of a carriage II. This carriage II is also provided with downwardly projecting marginal walls I2 at right angles to the walls In which overlie the central elevated portion I3 of a support I4. The support I4 is fixed to the casing I, being mounted on brackets 55 projecting inwardly therefrom. Preloaded ball bearings I5 are positioned between the walls I2 and the upstanding portion I3, mounting the carriage II for motion transverse to the direction of motion of the slide 8 thereon.

Th carriage II is provided with a rearwardly extended slideway block I6 having upright side walls I! between which rides a block I8 within which is journaled a pivot I9. Preloaded ball bearings 20 between the blocks I1 and I8 serve to confine the block I8 to a vertical motion with respect to the block I6. The pivot I9 is carried by an arm 2 I, the lower end of which is extended longitudinally of the casing I and at opposite ends is provided with journal bearings 22 and 23 supported on the fixed pivot members 24 and 25, respectively. Rocking of the arm 2| about the axes of these pivot members, therefore, produces lateral sliding of the carriage I I.

This arm 2| is rocked laterally by the lateral movement of a block 30 through which is threaded a screw 3|. tated in alternate directions by a driving mechanism such as is shown in the Flanders Patent No. 2,292,874, to which reference has already been made. The block 30 has a pair of spaced vertical guides 32 between which is mounted a crosshead 33 pivoted on a stud 34 secured to the arm 2| above the carriage II and the slide 8.

Atthe upper end of the arm 2| it is provided with a guideway 36 for the slidable reception of a stem 38. The rear end of this stem 38 carries a cam follower roll 39 which engages a face cam 40 fixed to the casing and so configured on its forward face as to cause the stem 38 to be moved axially as it is swung laterally across the face of the cam 4|] and is held thereag'ainst. The forward end of the stem 38 is slotted and receives between the sides of the slot a roll 42 journaled at This screw 3| may be ro-' the upper end of a lever 44. This lever 44 is fulcrumed at 45 on a bracket 46 carried by the arm 2| and its lower end has journaled thereon a roll 41 which bears against a, wall member 48 upstanding from'the slide 8. A spring 50 reacting between a pin 5! upstanding from the slide 8 and a hook 52 fixed to the back face of the partition follower 39 to traverse the cam 40.

Thus the carriage II is constrained to move in r a rectilinear path laterally of the casing while the slide 8 is constrained to move in a rectilinear path at right angles thereto, producing in and out motion of the stem 5,. By the use of the preloaded ball bearings, extremely accurate control of the rectilinear motionswithout lost motion is produced while these rectilinear motions are prodl fiedby pivoted members which can be closely controlled to avoid lost motion. By this construction the desired rectilinear motions of the truing tool are produced free from lost motion butwith- .out undue complication.

;- From the ioregoing description of: an embodi- 4 ment of this invention, it should be evident to those skilled in the art that various changes and modifications might be made without departing from the spirit or scope of this invention.

I claim:

. '1. A wheel truing device comprising a support, a first slide mounted for rectilinear motion on said support, a second slide'mounted on said first slide for rectilinear motion transverse to the motion of said first slide, a truing device carried by said second slide, a member pivoted to said sup-; port to swing in a plane parallel to the'di'rection of motion of one of said slides and operatively connected to said one slide, an element slidably carriedby said member to move transverse to said plane, a stationary cam along which said element 7 moves as said member swings on its pivot, a follower for saidcam carried by said element, a lever pivoted to said member on an axis transverse to the pivotal axis of said member, said lever having a portion engaged by said element and a portion 

